Some peo­ple are im­mune to Alzheimer’s symp­toms

Some peo­ple do not suf­fer mem­ory loss or men­tal de­cline even when they have Alzheimer’s dis­ease, sci­en­tists dis­cov­ered

China Daily (Hong Kong) - - SCIENCE - By SARAH KNAPTON

Some peo­ple are nat­u­rally im­mune to the symp­toms of Alzheimer’s even when they have the full-blown dis­ease, sci­en­tists have found. Sev­eral “su­per-agers” in their 90s who showed no sign of men­tal de­cline or mem­ory loss be­fore their death were all found to have the sig­na­ture plaques and tan­gles in their brains which sig­nal Alzheimer’s.

Sci­en­tists at North­west­ern Medicine in the US said they were amazed by the find­ings and are now look­ing for ge­netic, di­etary or en­vi­ron­men­tal rea­sons re­spon­si­ble.

“This is amaz­ing,” said Pro­fes­sor Changiz Geula, the lead in­ves­ti­ga­tor. “We never ex­pected it.

“It tells us there are some fac­tors that are pro­tect­ing their brains and mem­o­ries against the Alzheimer’s pathol­ogy of plaques and tan­gles. Now we have to find out what those are.

“We will look at ge­netic, di­etary and en­vi­ron­men­tal in­flu­ences that could con­fer pro­tec­tion for neu­rons against Alzheimer’s pathol­ogy.”

If sci­en­tists can find a pro­tec­tive fac­tor, it could help the el­derly and those with the Alzheimer’s pathol­ogy to avoid the dev­as­tat­ing symp­toms.

The post-mortems showed that de­spite hav­ing de­men­tia, the area of the brain re­spon­si­ble for mem­ory for­ma­tion was still largely in­tact.

“These find­ings clearly demon­strate the brains of some el­derly are im­mune to the toxic ef­fects of plaques and tan­gles,” added Prof Geula.

North­west­ern sci­en­tists stud­ied the brains of eight in­di­vid­u­als older than 90 who were se­lected for su­pe­rior per­for­mance in mem­ory tests com­pared to their same-age peers who had a nor­mal mem­ory test per­for­mance.

Three of those brains qual­i­fied patho­log­i­cally as hav­ing Alzheimer’s dis­ease, de­spite su­pe­rior mem­ory per­for­mance of the in­di­vid­u­als when they were alive.

When Prof Geula and col­leagues ex­am­ined nerve cells in the hip­pocam­pus, the part of the brain re­spon­si­ble for mem­ory for­ma­tion, they found cells in this area were rel­a­tively in­tact in the brains of el­derly peo­ple with full Alzheimer’s pathol­ogy and su­pe­rior mem­ory per­for­mance.

They also ex­am­ined five brains of Alzheimer’s de­men­tia pa­tients with full Alzheimer’s pathol­ogy.

Those brains showed sig­nif­i­cant cell death in the hip­pocam­pus. A sim­i­lar pat­tern was ob­served in other ar­eas of the brain that con­trol cog­ni­tive func­tion.

To count the neu­rons, the sci­en­tists ex­am­ined a se­ries of tis­sue sec­tions, which were stained to visu­al­ize neu­rons.

Then, us­ing a mi­cro­scope, they counted the num­ber of neu­rons in sec­tions of the hip­pocam­pus and the frontal cor­tex. When plaques and tan­gles ap­pear in the frontal cor­tex, it means Alzheimer’s pathol­ogy has spread through­out the brain.

Prof Geula’s lab is now em­bark­ing on a large-scale study to de­ter­mine the fac­tors, in­clud­ing ge­net­ics, that help pro­tect the brains of some el­derly against Alzheimer’s pathol­ogy.

The find­ings were pre­sented at the So­ci­ety for Neu­ro­science 2016 an­nual con­fer­ence in San Diego.

This is amaz­ing. We never ex­pected it. It tells us there are some fac­tors that are pro­tect­ing their brains and mem­o­ries against the Alzheimer’s pathol­ogy ... .” Pro­fes­sor Changiz Geula, the lead in­ves­ti­ga­tor for a group of sci­en­tists at North­west­ern Medicine in the US

PRO­VIDED TO CHINA DAILY

Sci­en­tists found some fac­tors that are pro­tect­ing brains and mem­o­ries against the Alzheimer’s pathol­ogy of plaques and tan­gles.

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